You can add DNS servers when adding IPv4 and IPv6 reconciliation policies. Setting DNS servers at the IP reconciliation policy level will supersede DNS servers set at any other levels.
For example, if you have set a DNS server at the global configuration level and you add a DNS server in an IP reconciliation policy, the DNS server set in that IP reconciliation policy will override the DNS server set the configuration level when running this particular reconciliation policy.
To add DNS servers in IP reconciliation policies, create a reconciliation policy according to the instructions detailed in Creating IP reconciliation policies. DNS servers are configured on the Optimization parameters tab when creating an IP reconciliation policy.